Porous, nitrogen-doped Li3V2(PO4)3/C cathode materials derived from oroxylum and their exceptional electrochemical properties in lithium-ion batteries

This work focused on the design and fabrication of porous, nitrogen-doped Li3V2(PO4)(3)/C cathode materials using a repeated impregnation synthesis process employing oroxylum as a template. The resulting Li3V2(PO4)(3)/C cathode materials were comprehensively analyzed using Fourier transform infrared spectroscopy, X-ray diffraction analysis, selected area electron diffraction, scanning electron microscopy and galvanostatic experiments. The Li3V2(PO4)(3)/C cathode materials of varying structure were prepared by various processing techniques using select precursors. The resulting porous, nitrogen-doped Li3V2(PO4)(3)/C cathode materials (IM-15) obtained using repeated impregnation exhibited a novel, overlapping hollow slab structure, which was covered by thin layers of porous, foamed Li3V2(PO4)(3)/C on the surface of IM-15. It was found that the porous, foamed Li3V2(PO4)(3)/C material was sandwiched between thin layers of adjacent Li3V2(PO4)(3)/C layers. IM-15 product exhibited an outstanding rate capability of 87.4 mAh g(-1) at the 10 C rate, and an excellent capacity retention of 96.9% after 1000 cycles at 5 C in the range of 3-4.3 V. These results were attributed to the porous, nitrogen-doped structure of the material, which provided a high diffusion coefficient and superior structural stability. The unique porous, nitrogen-doped structure was responsible for improving the rate capability and cycling stability of LIBs containing the subject experimental material.